PROMOS
Quebec :
Cable: Free transfer from another cable company
C-Cable: Free installation for new customer
V-Cable: 50% off installation for new customer
FTTN : 50% off installation for new customer

Ontario :
R-Cable: 75/10 for 32,95$ for 12 months + free installation if transferring from another cable company
Cable: Free transfer from another cable company
C-Cable: Free installation for new customer
FTTN : 50% off installation for new customer

Ebox is a great ISP and happy with them.
I only do the Ebox groupbuys every couple months with people when we accumulate 4 people. This way everyone gets best discounts.
My recommendation is finding people who are not in a rush and put them on standby, then contact everyone when 4 people come up. Most people are in no rush to change ISP's so that is not as rushed.
Good luck!